A full-automatic sample analysis device is used in the technical field of sample analysis such as biochemical analysis, immunoassay and fluoroimmunoassay. To detect substance contents in samples such as whole blood, plasma, serum or urea, bar codes on sample containers need to be scanned to input information of patients. Chinese patent CN201520158588.3 discloses an automatic rotation bar code scanning structure which includes a rotating disc rack, a plurality of test tube clamps, a scanning head for scanning bar codes on test tubes, and a driving mechanism for driving the test tube clamps to rotate; the test tube clamps are movably mounted on the rotating disc rack; the test tube clamps are driven by the driving mechanism to autorotate; the scanning head is arranged on the outer side of the rotating disc rack; driven wheels are arranged at the driving ends of the test tube clamps; the driving mechanism includes a driving motor and a driving wheel; the driving wheel is connected to a rotating shaft of the driving motor; the driving wheel is meshed with the driven wheels. With the rotation of the rotating disc rack, engagement of the driving wheel needs to be switched between different driven wheels, and the driving wheel can only be meshed with the driven wheel of a single test tube clamp at a moment, so the driving motor is arranged in a floating manner to achieve switching of engagement of the driving wheel.
By adopting the automatic rotation bar code scanning structure, positions of the test tubes do not need to be manually adjusted, so that the automation degree of sample test tube scanning is increased, however, as the structure is complex, the cost is relatively high, the number of components are numerous and multiple components match with each other, correspondingly the fault rate is likely to increase. For example, a driven wheel needs to be mounted on each test tube clamp on the rotating disc rack so as to achieve engagement with the driving wheel, and moreover, engagement of the driving wheel needs to be continuously switched between each driven wheel, a gear of the driving wheel is very likely to be clamped with a gear of the driven wheel in the switching process, the gears can be severely abraded in long-term use, and thus the requirements on control precision and gear hardness are high.